There are many types of diapers on the market that offer wide selections of functions. And many patents have been disclosed in this field. Most of them focus on the improvement of fluid absorption layers, inner protection layer material or elastic band of the diaper.
The widely used diapers are the common paper diapers that merely protect users from incontinence or urine overflow (namely the urination exceeds the fluid absorption saturation limit of the diaper) and prevent clothes and bed sheets from being smeared. When urine overflow occurs to an infant wrapped by the diaper and the parents do not replace the smeared diaper timely due to negligence, infant's hip could be infected with bacteria. For adult users who suffer from incontinence or loss of sense (such as after surgery and patient's sense not yet recovers), wearing such type of diaper is not comfortable. While some improvements have been made on the inner fluid absorption layer and elastic band, urine overflow could still happen and replacement is not being made timely.
To overcome the problem mentioned above, some vendors adopt modern electronic technologies and use electronic audio effect and electronic conductive circuits on the diaper. Whenever the diaper is soaked with excretion, the circuits become conductive and an electronic audio alarm is generated to alert nurses to replace the diaper. For instance, R.O.C. patent No. 210012 entitled “Improved diaper with a separated audio alarm” discloses such a technique that has a conductive circuit consisting of two parallel metal wires to detect urinous wet. But it cannot detect a larger area. In the event that urine seeps through between the two parallel metal wires or overflows and seeps through outside the two metal wires, it is not effective. Moreover, to lay conductive wires in the diaper increases fabrication cost and the price. As the diaper is a household goods that is consumed at huge quantity, to set the price too high will discourage consumers from buying.